// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
// 3. Neither the name of the copyright holders nor the names of its
//    contributors may be used to endorse or promote products derived from
//    this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
package xyz.noark.asm;

/**
 * A {@link FieldVisitor} that generates a corresponding 'field_info' structure,
 * as defined in the Java Virtual Machine Specification (JVMS).
 *
 * @see <a href=
 *      "https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.5">JVMS
 *      4.5</a>
 * @author Eric Bruneton
 */
final class FieldWriter extends FieldVisitor {

	/** Where the constants used in this FieldWriter must be stored. */
	private final SymbolTable symbolTable;

	// Note: fields are ordered as in the field_info structure, and those
	// related to attributes are
	// ordered as in Section 4.7 of the JVMS.

	/**
	 * The access_flags field of the field_info JVMS structure. This field can
	 * contain ASM specific access flags, such as
	 * {@link Opcodes#ACC_DEPRECATED}, which are removed when generating the
	 * ClassFile structure.
	 */
	private final int accessFlags;

	/** The name_index field of the field_info JVMS structure. */
	private final int nameIndex;

	/** The descriptor_index field of the field_info JVMS structure. */
	private final int descriptorIndex;

	/**
	 * The signature_index field of the Signature attribute of this field_info,
	 * or 0 if there is no Signature attribute.
	 */
	private int signatureIndex;

	/**
	 * The constantvalue_index field of the ConstantValue attribute of this
	 * field_info, or 0 if there is no ConstantValue attribute.
	 */
	private int constantValueIndex;

	/**
	 * The last runtime visible annotation of this field. The previous ones can
	 * be accessed with the {@link AnnotationWriter#previousAnnotation} field.
	 * May be <tt>null</tt>.
	 */
	private AnnotationWriter lastRuntimeVisibleAnnotation;

	/**
	 * The last runtime invisible annotation of this field. The previous ones
	 * can be accessed with the {@link AnnotationWriter#previousAnnotation}
	 * field. May be <tt>null</tt>.
	 */
	private AnnotationWriter lastRuntimeInvisibleAnnotation;

	/**
	 * The last runtime visible type annotation of this field. The previous ones
	 * can be accessed with the {@link AnnotationWriter#previousAnnotation}
	 * field. May be <tt>null</tt>.
	 */
	private AnnotationWriter lastRuntimeVisibleTypeAnnotation;

	/**
	 * The last runtime invisible type annotation of this field. The previous
	 * ones can be accessed with the {@link AnnotationWriter#previousAnnotation}
	 * field. May be <tt>null</tt>.
	 */
	private AnnotationWriter lastRuntimeInvisibleTypeAnnotation;

	/**
	 * The first non standard attribute of this field. The next ones can be
	 * accessed with the {@link Attribute#nextAttribute} field. May be
	 * <tt>null</tt>.
	 *
	 * <p>
	 * <b>WARNING</b>: this list stores the attributes in the <i>reverse</i>
	 * order of their visit. firstAttribute is actually the last attribute
	 * visited in {@link #visitAttribute}. The {@link #putFieldInfo} method
	 * writes the attributes in the order defined by this list, i.e. in the
	 * reverse order specified by the user.
	 */
	private Attribute firstAttribute;

	// -----------------------------------------------------------------------------------------------
	// Constructor
	// -----------------------------------------------------------------------------------------------

	/**
	 * Constructs a new {@link FieldWriter}.
	 *
	 * @param symbolTable where the constants used in this FieldWriter must be
	 *            stored.
	 * @param access the field's access flags (see {@link Opcodes}).
	 * @param name the field's name.
	 * @param descriptor the field's descriptor (see {@link Type}).
	 * @param signature the field's signature. May be <tt>null</tt>.
	 * @param constantValue the field's constant value. May be <tt>null</tt>.
	 */
	FieldWriter(final SymbolTable symbolTable, final int access, final String name, final String descriptor, final String signature, final Object constantValue) {
		super(Opcodes.ASM6);
		this.symbolTable = symbolTable;
		this.accessFlags = access;
		this.nameIndex = symbolTable.addConstantUtf8(name);
		this.descriptorIndex = symbolTable.addConstantUtf8(descriptor);
		if (signature != null) {
			this.signatureIndex = symbolTable.addConstantUtf8(signature);
		}
		if (constantValue != null) {
			this.constantValueIndex = symbolTable.addConstant(constantValue).index;
		}
	}

	// -----------------------------------------------------------------------------------------------
	// Implementation of the FieldVisitor abstract class
	// -----------------------------------------------------------------------------------------------

	@Override
	public AnnotationVisitor visitAnnotation(final String descriptor, final boolean visible) {
		// Create a ByteVector to hold an 'annotation' JVMS structure.
		// See
		// https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.16.
		ByteVector annotation = new ByteVector();
		// Write type_index and reserve space for num_element_value_pairs.
		annotation.putShort(symbolTable.addConstantUtf8(descriptor)).putShort(0);
		if (visible) {
			return lastRuntimeVisibleAnnotation = new AnnotationWriter(symbolTable, annotation, lastRuntimeVisibleAnnotation);
		} else {
			return lastRuntimeInvisibleAnnotation = new AnnotationWriter(symbolTable, annotation, lastRuntimeInvisibleAnnotation);
		}
	}

	@Override
	public AnnotationVisitor visitTypeAnnotation(final int typeRef, final TypePath typePath, final String descriptor, final boolean visible) {
		// Create a ByteVector to hold a 'type_annotation' JVMS structure.
		// See
		// https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.20.
		ByteVector typeAnnotation = new ByteVector();
		// Write target_type, target_info, and target_path.
		TypeReference.putTarget(typeRef, typeAnnotation);
		TypePath.put(typePath, typeAnnotation);
		// Write type_index and reserve space for num_element_value_pairs.
		typeAnnotation.putShort(symbolTable.addConstantUtf8(descriptor)).putShort(0);
		if (visible) {
			return lastRuntimeVisibleTypeAnnotation = new AnnotationWriter(symbolTable, typeAnnotation, lastRuntimeVisibleTypeAnnotation);
		} else {
			return lastRuntimeInvisibleTypeAnnotation = new AnnotationWriter(symbolTable, typeAnnotation, lastRuntimeInvisibleTypeAnnotation);
		}
	}

	@Override
	public void visitAttribute(final Attribute attribute) {
		// Store the attributes in the <i>reverse</i> order of their visit by
		// this method.
		attribute.nextAttribute = firstAttribute;
		firstAttribute = attribute;
	}

	@Override
	public void visitEnd() {
		// Nothing to do.
	}

	// -----------------------------------------------------------------------------------------------
	// Utility methods
	// -----------------------------------------------------------------------------------------------

	/**
	 * Returns the size of the field_info JVMS structure generated by this
	 * FieldWriter. Also adds the names of the attributes of this field in the
	 * constant pool.
	 *
	 * @return the size in bytes of the field_info JVMS structure.
	 */
	int computeFieldInfoSize() {
		// The access_flags, name_index, descriptor_index and attributes_count
		// fields use 8 bytes.
		int size = 8;
		// For ease of reference, we use here the same attribute order as in
		// Section 4.7 of the JVMS.
		if (constantValueIndex != 0) {
			// ConstantValue attributes always use 8 bytes.
			symbolTable.addConstantUtf8(Constants.CONSTANT_VALUE);
			size += 8;
		}
		// Before Java 1.5, synthetic fields are represented with a Synthetic
		// attribute.
		if ((accessFlags & Opcodes.ACC_SYNTHETIC) != 0 && symbolTable.getMajorVersion() < Opcodes.V1_5) {
			// Synthetic attributes always use 6 bytes.
			symbolTable.addConstantUtf8(Constants.SYNTHETIC);
			size += 6;
		}
		if (signatureIndex != 0) {
			// Signature attributes always use 8 bytes.
			symbolTable.addConstantUtf8(Constants.SIGNATURE);
			size += 8;
		}
		// ACC_DEPRECATED is ASM specific, the ClassFile format uses a
		// Deprecated attribute instead.
		if ((accessFlags & Opcodes.ACC_DEPRECATED) != 0) {
			// Deprecated attributes always use 6 bytes.
			symbolTable.addConstantUtf8(Constants.DEPRECATED);
			size += 6;
		}
		if (lastRuntimeVisibleAnnotation != null) {
			size += lastRuntimeVisibleAnnotation.computeAnnotationsSize(Constants.RUNTIME_VISIBLE_ANNOTATIONS);
		}
		if (lastRuntimeInvisibleAnnotation != null) {
			size += lastRuntimeInvisibleAnnotation.computeAnnotationsSize(Constants.RUNTIME_INVISIBLE_ANNOTATIONS);
		}
		if (lastRuntimeVisibleTypeAnnotation != null) {
			size += lastRuntimeVisibleTypeAnnotation.computeAnnotationsSize(Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS);
		}
		if (lastRuntimeInvisibleTypeAnnotation != null) {
			size += lastRuntimeInvisibleTypeAnnotation.computeAnnotationsSize(Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS);
		}
		if (firstAttribute != null) {
			size += firstAttribute.computeAttributesSize(symbolTable);
		}
		return size;
	}

	/**
	 * Puts the content of the field_info JVMS structure generated by this
	 * FieldWriter into the given ByteVector.
	 *
	 * @param output where the field_info structure must be put.
	 */
	void putFieldInfo(final ByteVector output) {
		boolean useSyntheticAttribute = symbolTable.getMajorVersion() < Opcodes.V1_5;
		// Put the access_flags, name_index and descriptor_index fields.
		int mask = useSyntheticAttribute ? Opcodes.ACC_SYNTHETIC : 0;
		output.putShort(accessFlags & ~mask).putShort(nameIndex).putShort(descriptorIndex);
		// Compute and put the attributes_count field.
		// For ease of reference, we use here the same attribute order as in
		// Section 4.7 of the JVMS.
		int attributesCount = 0;
		if (constantValueIndex != 0) {
			++attributesCount;
		}
		if ((accessFlags & Opcodes.ACC_SYNTHETIC) != 0 && useSyntheticAttribute) {
			++attributesCount;
		}
		if (signatureIndex != 0) {
			++attributesCount;
		}
		if ((accessFlags & Opcodes.ACC_DEPRECATED) != 0) {
			++attributesCount;
		}
		if (lastRuntimeVisibleAnnotation != null) {
			++attributesCount;
		}
		if (lastRuntimeInvisibleAnnotation != null) {
			++attributesCount;
		}
		if (lastRuntimeVisibleTypeAnnotation != null) {
			++attributesCount;
		}
		if (lastRuntimeInvisibleTypeAnnotation != null) {
			++attributesCount;
		}
		if (firstAttribute != null) {
			attributesCount += firstAttribute.getAttributeCount();
		}
		output.putShort(attributesCount);
		// Put the field_info attributes.
		// For ease of reference, we use here the same attribute order as in
		// Section 4.7 of the JVMS.
		if (constantValueIndex != 0) {
			output.putShort(symbolTable.addConstantUtf8(Constants.CONSTANT_VALUE)).putInt(2).putShort(constantValueIndex);
		}
		if ((accessFlags & Opcodes.ACC_SYNTHETIC) != 0 && useSyntheticAttribute) {
			output.putShort(symbolTable.addConstantUtf8(Constants.SYNTHETIC)).putInt(0);
		}
		if (signatureIndex != 0) {
			output.putShort(symbolTable.addConstantUtf8(Constants.SIGNATURE)).putInt(2).putShort(signatureIndex);
		}
		if ((accessFlags & Opcodes.ACC_DEPRECATED) != 0) {
			output.putShort(symbolTable.addConstantUtf8(Constants.DEPRECATED)).putInt(0);
		}
		if (lastRuntimeVisibleAnnotation != null) {
			lastRuntimeVisibleAnnotation.putAnnotations(symbolTable.addConstantUtf8(Constants.RUNTIME_VISIBLE_ANNOTATIONS), output);
		}
		if (lastRuntimeInvisibleAnnotation != null) {
			lastRuntimeInvisibleAnnotation.putAnnotations(symbolTable.addConstantUtf8(Constants.RUNTIME_INVISIBLE_ANNOTATIONS), output);
		}
		if (lastRuntimeVisibleTypeAnnotation != null) {
			lastRuntimeVisibleTypeAnnotation.putAnnotations(symbolTable.addConstantUtf8(Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS), output);
		}
		if (lastRuntimeInvisibleTypeAnnotation != null) {
			lastRuntimeInvisibleTypeAnnotation.putAnnotations(symbolTable.addConstantUtf8(Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS), output);
		}
		if (firstAttribute != null) {
			firstAttribute.putAttributes(symbolTable, output);
		}
	}

	/**
	 * Collects the attributes of this field into the given set of attribute
	 * prototypes.
	 *
	 * @param attributePrototypes a set of attribute prototypes.
	 */
	final void collectAttributePrototypes(final Attribute.Set attributePrototypes) {
		attributePrototypes.addAttributes(firstAttribute);
	}
}
